The present disclosure relates to three-dimensional (3D) models built with digital manufacturing systems using layer-based additive techniques. In particular, the present disclosure relates to the use of support structures for building and transporting 3D models.
Digital manufacturing systems are used to build 3D models from digital representations of the 3D models (e.g., STL format files) using one or more layer-based additive techniques. Examples of commercially available layer-based additive techniques include fused deposition modeling, ink jetting, selective laser sintering, electron-beam melting, and stereolithographic processes. For each of these techniques, the digital representation of the 3D model is initially sliced into multiple horizontal layers. For each sliced layer, a build path is then generated, which provides instructions for the particular digital manufacturing system to form the given layer. For deposition-based systems (e.g., fused deposition modeling and ink jetting), the build path defines the pattern for depositing roads of modeling material from a moveable deposition head to form the given layer. Alternatively, for energy-application systems (e.g., selective laser sintering, electron-beam melting, and stereolithographic processes), the build path defines the pattern for emitting energy from a moveable energy source (e.g., a laser) to form the given layer.
For example, in a fused deposition modeling system, modeling material is extruded from a moveable extrusion head, and is deposited as a sequence of roads on a substrate in an x-y plane based on the build path. The extruded modeling material fuses to previously deposited modeling material, and solidifies upon a drop in temperature. The position of the extrusion head relative to the substrate is then incremented along a z-axis (perpendicular to the x-y plane), and the process is then repeated to form a 3D model resembling the digital representation.
In fabricating 3D models by depositing layers of modeling materials, supporting layers or structures are typically built underneath overhanging regions of 3D models under construction, which are not supported by the modeling material itself. A support structure may be built utilizing the same deposition techniques by which the modeling material is deposited. The host computer generates additional geometry acting as a support structure for the overhanging or free-space segments of the 3D model being formed. The support material adheres to the modeling material during fabrication, and is removable from the completed 3D model when the build process is complete.
In many situations, designers may not have direct access to digital manufacturing systems, or may only require a limited number of 3D models to be manufactured. In these cases, it may be more efficient and cost effective for the designers to have professional manufacturers that are experts with the digital manufacturing systems to perform the work. For example, customers may submit their digital representations to a manufacturer of 3D models, and the manufacturer may build the 3D models using one or more digital manufacturing systems. After the build operations are complete, the manufacturer may then ship the resulting 3D models to the customers. While this provides an efficient and cost effective means for customers to attain built 3D models, many 3D models may be subject to potentially damaging conditions during packaging, storage, and/or shipping. This is particularly true for 3D models that contain fine features. Thus, there is an ongoing need for techniques that increase the safety of 3D models during storage and transit to customers.